我正在尝试使用 Swift 5 中的 AVAudioPlayer 实例从后台线程播放声音。大多数情况下,它会成功。但是有时音频播放器无法播放声音。
似乎调用 play() 两次,或者连续调用 prepareToPlay() 然后 play() 以某种方式解决了问题,但这对我来说似乎不是一个好的解决方案,因为我担心这仍然不是保证播放成功。
func setUpAudio() {
AVAudioSession.sharedInstance().perform(NSSelectorFromString("setCategory:error:"), with: AVAudioSession.Category.playback)
try! AVAudioSession.sharedInstance().setActive(true)
NotificationCenter.default.addObserver(self, selector: #selector(handleInterruption), name: AVAudioSession.interruptionNotification, object: nil)
}
func startNewAudio() {
let destinationData = Destinations.getDestinations()
var audio = destinationData[currentStop]!["audio"] as! String
if inTransit {
audio = destinationData[Paths.tourOrder[currentIndex + 1]]!["transit_audio"] as! String
}
let sound = NSURL(fileURLWithPath: Bundle.main.path(forResource: audio, ofType: "mp3", inDirectory: "audio")!)
try! audioPlayer = AVAudioPlayer(contentsOf: sound as URL)
audioPlayer.delegate = self
currentTime = 0
setPlay()
}
func setPlay() {
paused = false
pauseButton.setImage(UIImage(named: "pause"), for: .normal)
pauseButton.isEnabled = true
audioPlayer.currentTime = currentTime
DispatchQueue.global(qos: .background).async {
self.audioPlayer.play()
print(self.audioPlayer.isPlaying) // returns false sometimes
}
}
我按以下顺序调用方法:
setUpAudio()
startNewAudio()
setPlay()
我无法弄清楚问题所在——我真的只想调用一次 play() 并让一切正常。